Chemistry of Life – Lecture Review

Flashcards covering key points from Chapter 2: The Chemistry of Life, including matter, elements, compounds, macromolecules, carbohydrates, lipids, proteins, nucleic acids, and energy content.

What is matter?

Anything that has mass and occupies space.

Define an element.

The simplest form of matter; a substance that cannot be broken down into two or more different substances.

What is a compound?

A chemical combination of atoms from two or more elements.

Give an example of a compound mentioned in the lecture.

Carbon dioxide (CO₂).

What are macromolecules?

Large polymers built from repeating monomer subunits.

Name the three classes of macromolecules that are polymers.

Carbohydrates, proteins, and nucleic acids.

What distinguishes an organic molecule from an inorganic one?

Organic molecules contain carbon-to-carbon (C–C) or carbon-to-hydrogen (C–H) bonds; inorganic molecules do not.

List the four major categories of organic compounds important to humans.

Carbohydrates, proteins, lipids, and nucleic acids.

What is the building block (monomer) of carbohydrates?

A monosaccharide (simple sugar).

Differentiate between monosaccharides, disaccharides, and polysaccharides.

Monosaccharide: one sugar unit; Disaccharide: two sugar units; Polysaccharide: many sugar units (complex).

Give an example of a hexose monosaccharide.

Glucose.

What is the primary function of carbohydrates in the body?

To provide quick energy.

What chemical process breaks polysaccharides into monosaccharides?

Hydrolysis.

Name the three monosaccharides highlighted in the notes.

Glucose, fructose, and galactose.

What disaccharide is commonly known as table sugar?

Sucrose.

Which complex carbohydrate stores glucose in plants?

Starch.

What elements make up lipids?

Carbon and hydrogen with relatively little oxygen.

Contrast saturated and unsaturated fatty acids at room temperature.

Saturated fats are solid; unsaturated fats are liquid.

Why are saturated fats often called “bad” fats?

They are associated with negative health effects such as raising unhealthy cholesterol levels.

Provide two examples of saturated fats.

Butter and margarine.

Provide two examples of unsaturated fats.

Vegetable oil and corn oil.

List four other types of lipids besides fats and oils.

Phospholipids, waxes, steroids, and triglycerides.

What is the main biological function of lipids?

Long-term energy storage.

Besides energy storage, give two other functions of lipids.

They form cell membranes and insulate nerve cells (myelin).

Which biomolecule contains the greatest number of C-H bonds—and thus the most energy per gram?

Lipids (fats).

What are the monomers of proteins?

Amino acids.

How many essential amino acids cannot be synthesized by the human body?

Eight.

What type of bond links amino acids together?

A peptide bond.

What is the polymer formed from many amino acids?

A polypeptide.

Name three functions of proteins in the body.

Provide structure and strength, act as enzymes/hormones/antibodies, and transport molecules such as hemoglobin.

What three components make up a nucleotide?

A 5-carbon sugar, a phosphate group, and a nitrogenous base.

Name the two types of nucleic acids.

DNA and RNA.

Which nitrogenous base is found only in DNA?

Thymine.

Which nitrogenous base is found only in RNA?

Uracil.

Give two structural differences between DNA and RNA.

DNA is double-stranded with deoxyribose sugar; RNA is single-stranded with ribose sugar.

What is the primary function of DNA?

To store and transmit genetic (hereditary) information.

What is the role of RNA in cells?

It carries genetic information from DNA and assists in protein synthesis.

Explain the relationship between monomers and polymers.

Polymers are long molecules made of repeating monomer units.

According to the lecture, what correlates with the amount of energy a biomolecule holds?

The number of carbon-hydrogen (C-H) bonds it contains.